Tabs that can be mounted on file folders or storage partitions for indexing, marking, cataloguing, listing or sorting purposes are well known in the art. Typically, they are made of extruded or molded plastic material and have means for attachment to an edge of a partition or a paper or plastic sheet. They are typically designed to be removable so that they can be repositioned or taken off entirely. For example, a variety of tabs are designed for use with hanging file folders. These folders typically have metal support bars attached at their upper edges, and tabs are often mounted along the upper edge of such a folder. Such tabs are generally provided with means at or near their lower edges for engaging the folder top edge and/or the support bar. The folder edge often has holes or slots into which the tab or some portion thereof fits so that an indexing portion of the tab projects beyond the edge of the folder.
Ideally, it should be relatively easy for a user to mount or reposition an indexing or marking tab on a folder or partition, but the tab should also remain securely in place once it is mounted. It should likewise be easy to remove the tab without damaging it or the surface on which it has been mounted. The amounts of effort and dexterity needed to mount or remove a tab should be minimal. Prior art tabs often fail to meet these criteria, for various reasons.
It is known in the art of hanging file folders, for example, to use a stiff plastic tab for clamping or clipping onto the top edge of the folder. Such tabs commonly have a front portion, on which indexing or labeling information can be written or attached, and a rear portion, which forms the reverse or back of the tab. Typically, such tabs are molded and have two prongs extending downwardly from, for example, the front of the tab at the edges thereof. A third prong may extend downwardly from the central portion of, for example, the rear of the tab, thus forming a clip configuration, whereby the first two prongs press against one face of the folder edge, and the third prong grips the opposite face of the folder edge. The means by which such a tab grips the folder edge are two-fold: first, the three prongs exert a squeezing force on the folder edge in a manner similar to that exerted by a paper clip that is clipped to the edge of a piece of paper. Second, the tab is provided with one or more protuberances on the third prong configured and adapted for insertion into corresponding regularly-spaced holes in the folder's upper edge and/or in the support bar. When one such protuberance is molded into the tab's third prong, it is typically centrally located on the face of the prong that presses against the folder edge. The single protuberance is inserted into a hole in the folder edge and/or the support bar to create an interlocking fit therebetween. In prior art tabs having two protuberances on the third prong, the protuberances are spaced apart from each other so that they engage adjacent holes in the folder edge and/or in the support bar.
Engagement of the protuberance(s) with the holes in the folder edge and/or the support bar ensures that the tab will not move out of position once it is mounted, but this arrangement also makes it difficult to remove the tab, because it resists being pulled or twisted out of engagement with the folder and/or in the support bar holes. Attempts to remove or re-position this kind of tab easily result in tearing the file folder, which is typically made of paper. When an attempt is made to remove the tab by bending it and pulling it off the folder, for example, the tight fit between the tab and the folder tends to cause friction and wear along the top edge of the folder and in the holes or slots from which the tab is being removed. Removing such a tab also can easily cause one of its protuberances to break off, thus rendering the damaged tab virtually useless. Also, tabs with such protuberances are limited in that they must be used with file folders having the appropriate configuration of regularly spaced holes, and because positioning of the tab is restricted to the predetermined placement of the holes.
Some indexing tabs known in the art are made of extruded plastic. Such tabs typically engage the top edge of the folder by exerting pressure thereupon with downwardly extending legs that may be angled inwardly toward one another to provide one or more contact points for gripping the folder. The cross-section of an extruded tab is limited by the fact that the extrusion process produces a profile with a constant cross-section. Therefore, extruded tabs are not produced with protuberances such as those described above on molded tabs. Instead, it is typical for the downwardly extending legs to exert pressure against the folder along the entire width of the extruded tab. Sufficient clamping pressure must be exerted to prevent the tab from being knocked out of position or accidentally pulled off the folder. To provide sufficiently high clamping pressure, the tab is typically formed of relatively inflexible plastic, and the downwardly extending legs are typically angled toward each other so that they are able to squeeze a folder edge that is inserted between them. The rigidity of the plastic tab, combined with the orientation of the downwardly extending legs toward each other, enable a tight fit to be achieved between the tab legs and the folder; therefore, the tab tends to stay where it is mounted. Because it is so inflexible, however, it is difficult and awkward to mount, remove or reposition the tab. A user must exert a fair amount of force to push the tab onto a folder or to yank it off. Because the tab does not bend easily, it tends to cause friction and wear on the folder when the user applies or removes the tab, with the result that the folder is often ripped, frayed or bent. Furthermore, the tab itself is easily damaged, because the relatively inflexible downwardly extending legs tend to crack or snap off easily when force is applied to them. Thus, instead of being reusable or re-positionable, the tab often is thrown away after only one use, because it breaks so easily.
Therefore, there exists a need for a tab that can be mounted on, repositioned along and removed from a folder or partition with smooth, uncomplicated motions, wherein damage to the tab and the folder is minimized during such operations. These objects are all fulfilled by the positionable indexing tab of the present invention.